RCBS Full-Length Die Sets are precision-machined from proprietary die steel to exacting tolerances, followed by a meticulous finishing process that ensures top-tier quality for hand-loaders. Each set includes a Full-Length Sizing Die and a Bullet Seating Die, both designed for reloading bottleneck cases. The Full-Length Sizer Die features an Expander-Decapping Unit that sizes the case, de-primes and expands the neck to accept the bullet, all while maintaining SAAMI minimum cartridge dimensions. Vents in the die prevent damage from trapped air and excessive lubricant. The headspace is held to tight tolerances, preventing changes in the case body length during full-length sizing. The included Seater Die is equipped with a built-in roll crimper, securely seating the bullet while ensuring reliable performance.